[mo24 (OP)]

Hello my friends.

A buddy of mine has a theory about a certain controversial device effects on the human body. This device purportedly uses VLF radio waves to destroy pathogens. I do not share his opinion about it, and am looking for some hard scientific fact to disprove it.

The first step. I would like to find out what EM wave frequencies are required to penetrate certain parts of the body and what power output is required to do so. For instance, the skin, the blood vessels, muscle, fat, or bone. I realize that EM waves with the shortest wave length (highest frequency) penetrate the body best, but my interest lies in VLF frequencies in the range of 1Hz to 10KHz. What parts of the body could such EM waves penetrate, and what amount of power would be required for them to do so?

If you would know of a website that would help answer these questions, I would be very grateful. Thanks.

[wim]

VLF(very low frequency) these are ordinary radiowaves, the waves that your little antenna on your radio receives. Wether these have healing effects i couldn't say because there are a lot of things that we do not understand butt does work like homeopathy, I don't "use" this technics i go to a regular doctor butt these things really work for certain people...
So I believ your gonna get an endless discussion wich are the best most of the time[]

[Soul Surfer]

The penetration of radio waves into saline solutions (like the body) is about one wavelength so for any waves longer than about 1 metre or 300 MHz (just lower than the bottom end of UHF television frequencies) the radio waves penetrate right through the human body and the energy in the waves couples into tissue very badly. The lower the frequency the worse the coupling for radio waves. In the frequency range 1Hz to 10khz this coupling is almost non existant unless the source is in direct contact with the body and a ground to complete the circuit in which case the standard rules for safety from electric shocks apply.  

It is also extremely difficult to radiate radio waves at such low frequencies unless you have antennas many miles across because the wavelengths vary from 300,000 KM to 30KM

In general the biological effects of radio waves is limited to heating by the deposition of energy and to generate transmit and interceot a significant amount of energy with a body at the low frequency you suggest is almost impossible and extremely inefficient.

One interesting fact it is possible to cook meat with medium frequency radio of a few tens of MHz.  We did some research into it some years ago.  The joints cooked were extremely tasty.  Much tastier than microwave cooking but it was technically quite difficult to do becase the meat had to be neatly cylindrical and mounted between two flat plates like a capacitor (a bit like a supermarket joint!)  but we could do a good joint to a turn in a few minutes!  The experiments were greatly appreciated around lunchtime! but the institutional caterers did not want to bother with an extra piece of kit that just cooked prcisely shaped lumps of meat (no matter how nicely or quickly) when a normal cooker or microwave would do most things,

Learn, create, test and tell
evolution rules in all things
God says so!

[G-1 Theory]

Dear Mo24;

  Sorry, To tell you that all, VLF, UHF, WLF, will pass through the human body with out doing anything to it.
  But EM fields of the MRIs
do have the ablity to energize the human atoms to then release photons that then can be detected and shown on a cpmputer.
  We ham radio operators have used all of these VHF, UHF WHF, microwaves all of the time.

Call sign KE5RLS


"Learn the facts and go on from there, and never stop asking questions."

Admiral Rickover

[another_someone]

I am a little curious as to what he regards as a device to transmit VLF signals.  Transmitting VLF signals efficiently, because of their long wavelength, usually requires some pretty large aerials.

VLF signals carry very little energy, so unless he his throwing out a massive amplitude of signal (is he broadcasting using a multi kilowatt, or even a megawatt, transmitter?) they are not going to impart much energy to the human body (let alone to bacteria, which because of their smaller size, will be even less efficient at extracting energy from such a long wave).

There are those who would question the effects of prolonged VLF exposure (over many months or years), where one might speculate upon the cumulative impact of effects that are too small to be observed in the short term, but this is very different from a device that one is exposed to for a short duration.

George

[mo24 (OP)]

Thank you very much for the responses, although I am a bit late in replying.

I've had time to view the schematics of the device in question. It apparently functions off of a basic signal generator, amp, and coil. It is quite simple actually. The model he is concerned with uses an 1800 Watt amp to magnify the signal.

Ideally, the device would be designed for extremely close proximity use - within 2-3 feet of the coil. Large scale propagation would be unimportant.

The theory behind it is that everything has a resonant frequency. Combining a set of frequencies from EM waves (all of which happen to fall in the 0Hz-10Kz range) in a given pattern to disrupt certain parts of the cellular makeup of a bacteria, for instance, can result in the eventual disablement of said bacteria, rendering it harmless.

This is an excellent start. Do you have any more comments about why  this device could not possibly work as theorized from a scientific standpoint?

[Mystericon]

Sounds... Interesting...

As a true nerd, I'll start by bringing Star Trek into this. I watched Insurrection the other day. Aparrently there was a planet with rings that constantly emitted VLF waves which had regenerative properties allowing all life on the planet to be immortal. I know, its not real but in someways Star Trek is quite scientifically accurate. Anywho... its a nice idea but I doubt it does work in any way...

"If a man is a fool, you don't train him out of being a fool by sending him to university. You merely turn him into a trained fool, ten times more dangerous."
Desmond Bagley.